The present invention relates to a device for suppressing voltage drops.
More particularly it relates to a device for suppressing voltage drops in apparatuses which can be connected with a battery via at least two lines for their voltage supply.
The control or regulating of the engine of a motor vehicle and also the control of anti-lock systems (ABS) or drive slip regulators (ASR) is conventionally effected at present by means of a control apparatus. The control apparatus is supplied with voltage by the battery of the motor vehicle. Since special demands are made on the regularity of this voltage a separate voltage regulator is usually associated with the control apparatus.
In a control apparatus voltage supply described in DE-P 40 41 620, which does not have a prior publication date, a first input of the control apparatus is permanently supplied with voltage via a first line. There is no provision for interrupting the voltage supply when the engine is switched off.
A second input of the control apparatus is supplied by connected battery voltage via a second line. The ignition switch is connected between the battery and the control apparatus input. When the engine is switched off, the ignition switch is opened and voltage is no longer applied to the corresponding control apparatus input.
Such a voltage supply has proven advantageous because a motor vehicle has different consumers, some of which must be supplied with voltage constantly even when the engine is switched off, while others must be supplied with voltage only during operation.
However, the arrangement described in DE-P 40 41 620 has the disadvantage that the permanent voltage supply or connected battery voltage is temporarily interrupted in an impermissible manner during disturbances, e.g. temporary voltage drops which can occur during rough operation of a motor vehicle, and this interruption then leads to a resetting of the control apparatus. Since a reinitializing of the microcomputer system of the control system is required after such a resetting, no controlling of the fuel injection or ignition, for example, can be effected by the control apparatus during this initializing period.